The general aims of the proposed project are twofold: a) to relate individual combat and reentry experiences of Vietnam veterans to their current psychological functioning, and b) to investigate various treatment modes for posttraumatic stress disorder. The specific goals are to 1) delineate diagnostic categories in an outreach population, 2) to denote specific aspects of combat and reentry experiences most predictive of psychopathology, 3) to investigate coping modes and social supports as modifiers of the stress-outcome relationship, and 4) to evaluate the relative efficacy of three treatment approaches for posttraumatic stress disorder which are tied into theoretical notions about the etiology and maintenance of the disorder. The design calls for the interviewing of 350 veterans generated through two outreach programs currently underway at a national level. The measures utilized will cover the areas of combat and reentry stress, previous history and demographics, coping modes, social support networks, current and past diagnoses of psychiatric disorders, and current symptom complaints. The pre-service variables, stresses, coping modes and social supports will be used to predict current diagnoses and functioning using multivariate, hierarchical techniques. Subjects meeting the DSM-III criteria for posttraumatic stress disorder will be assigned to one of three treatment approaches: individual focal psychotherapy, rap group, or medication, for four months. Outcome data will be collected on these subjects again at four months (following treatment) and one year. A group of subjects qualifying for treatment but refusing will also be followed as a comparison. Long-term goals of the project are 1) to help military planners alter circumstances of combat to reduce later impairment, and to provide a better transition from military to civilian life, 2) to assist clinicians in identifying veterans at risk for posttraumatic stress disorder, 3) to assist clinicians in focusing on experiences and surrounding circumstances most likely to be causing or maintaining the disorder, and 4) to suggest the most effective treatment modalities for individuals suffering from posttraumatic stress disorder.